Study links sugary drinks with high blood pressure

LONDON (Reuters Life!) - Scientists have linked drinking sugary drinks like fizzy cola and fruit drinks with high blood pressure and say their findings suggest that cutting both sugar and salt intake could help reduce the risk.

High blood pressure, or hypertension, is a major risk factor for heart disease, which is the leading cause of death worldwide.

In a study of more than 2,500 people in the United States and Britain, researchers found that for every extra can of sugary drink consumed per day, participants had higher systolic blood pressure by an average of 1.6 mmHg and a higher diastolic reading by an average of 0.8 mmHg.

This difference was significant even after adjusting for factors such as weight and height, the scientists wrote on Monday in a study in the journal Hypertension.

Blood pressure is at its highest when the heart beats, pumping the blood. This is called systolic pressure. Between beats, when the heart is resting, the blood pressure falls. This is the diastolic pressure.

Experts say someone with a blood pressure level in millimetres of mercury (mmHg) of 135 systolic over 85 diastolic is twice as likely to have a heart attack or a stroke as someone with a reading of 115 over 75.

In this study, the link between sugary drinks and higher blood pressure was especially strong in people who ate a lot of salt as well as sugar, the researchers said, supporting long-established findings that high salt intake can lead to high blood pressure.

"It's widely known that if you have too much salt in your diet, you're more likely to develop high blood pressure. The results of this study suggest that people should be careful about how much sugar they consume as well," said Paul Elliott of Imperial College London, who worked on the study.

The researchers analysed data from 2,696 volunteers aged between 40 and 59, in eight areas of the United States and two areas of Britain.

Over an average period of three weeks, the volunteers were asked four times to report what they had eaten in the preceding 24 hours, as well as giving urine samples and having their blood pressure measured.

The researchers also found that people who drink more sugary drinks tended to have more unhealthy diets in general. As well as eating more sugar, people who drank more than one sugary drink a day consumed more calories on average, as well as less fibre and minerals.

Those who didn't drink sugary drinks had a lower body mass index (BMI) on average than those who drank more than one a day.

In a statement, the American Beverage Association (ABA) said that the blood pressure differences seen in the study were "inconsequential," and that the study could not prove a cause-effect relationship.

Ian Brown, another Imperial College researcher who worked with Elliott and U.S. colleagues agreed that it could not establish causal links because it was a population study.

"It can't say definitively that sugary drinks raise your blood pressure, but it's one piece of the evidence in a jigsaw puzzle that needs to be completed," Brown said in a statement.

"In the meantime, we would advise people who want to drink sugar-sweetened beverages should do so only in moderation," he said.